DTC B1B8E: Seat Slide Sensor (Power Supply Side) Short Circuit: Diagnosis

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

Required Special Tools:

MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V. C. I).
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958. Refer to "HOW TO CONNECT THE SCAN TOOL ".
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.

NO : Repair the CAN bus line (Refer to DIAGNOSIS ).

Fig 1: Connecting Special Tool MB991910 To Data Link Connector
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Go to Step 3.

NO : There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
STEP 3. Check the seat slide sensor circuit. Measure the voltage at the occupant classification-ECU connector D-39-2.
1. Disconnect occupant classification connector-ECU connector D-39-2.
2. Disconnect seat slide sensor connector D-32.
3. Turn the ignition switch to the "ON" position.
  CAUTION: Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.
4. Measure the voltage between D-39-2 harness side connector terminals 27, 29 and body ground.
  Voltage should measure 0 volt.
Q: Is the measured voltage within the specified range?

YES : Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1B8E sets, replace the slide adjuster (LH) (Refer to FRONT SEAT ASSEMBLY ).

NO : Go to Step 4.

Fig 2: Measuring Voltage Between D-39-2 Harness Side Connector Terminals 27, 29 And Body Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 4. Check the harness wires for short circuit to power supply between the occupant classification-ECU connector D-39-2 (terminal No. 27 and 29) and seat slide sensor connector D-32 (terminal No. 2 and 1).
Q: Are the harness wires between occupant classification-ECU connector D-39-2 (terminal No. 27 and 29) and seat slide sensor connector D-32 (terminal No. 2 and 1) in good condition?

YES : Go to Step 5.

NO : Repair the harness wires between the occupant classification-ECU connector D-39-2 and seat slide sensor connector D-32. Then go to Step 5.
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set to the occupant classification-ECU.
1. Erase the DTC.
2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
3. Check if DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC B1B8E set?

YES : Replace the slide adjuster (LH) (Refer to FRONT SEAT ASSEMBLY ).

NO : The procedure is complete.